Just FYI. One of the biggest headaches I've had on TH2Gs is not realizing I have a single link DVI-D or a DVI-I cable.
If you don't have a Dual Link DVI-D cable, you'll have the same headaches. The larger images sizes don't work on single link. And if you use a DVI-I the TH2G will default to analog and won't do the majority of the configurations.
I have only one of these and hate it. There were artifacts on 10.6 And 10.5.x. It's useless really considering I have to convert everything anyway. I might change my mind once someone creates a nice reliable MDP fibre/copper extender.